Messages

1

General Radio Discussion / Re: Empty HF frequency band for emergency coms

« on: January 19, 2021, 2130 UTC »

NVIS during the day. 3 to 7MHz.

Keep an eye on MUF on your local ionosonde.

Very reliable and what pirates and the military have used for years.

Forget CB frequencies, useless unless there's sunspots!

Are you one of those prepping types?

Str.

OK, makes sense. I wasn't a prepping type until recently. You're in the UK, so it probably doesn't seem as important there.

Consider too, do you want your coms monitored by just anyone or are we talking to a specific station?  If you want coms that don't need to be secured for some reason, Amateur bands will be full of voices that may be able to help out in a given situation, depending on the type of emergency that is.  OpSec however is a major concern if you want to live a quiet undisturbed life after a major societal issue.  Listening will yield truths.  Why they never paid more attention to HF radio coms in Walking Dead in the early seasons is totally beyond me.

I have often said that just hearing a transmission is information on it's own level.  Hearing a lot of traffic means one thing, hearing routine traffic is another.  Hearing unwanted visitors on VHF means Danger Close while a fading HF signal is not likely a threat.  Stuff to learn.

Personally I doubt we are on the brink just yet.  I do always suggest people do what our great grandparents did and just be prepared to be on your own for a while, if nothing else in case of natural disaster or say some nasty virus keeps us all on lock down.  I hear the Left Coast had a quake just the other day.  "Learn to Swim" - Tool

My 2 pennies worth,
DB, out.

I'd mostly just be talking with another couple stations, but I wouldn't mind if people were listening for the most part. They probably didn't pay more attention to HF because most novices or random people that get ahold of a "ham radio" use a VHF radio. For some reason it's become like the defacto standard even though HF is probably more useful. Like it was pretty hard for me to find cheap HF radios. Almost all of the cheaper ham radios are VHF and I think that's probably what most "preppers" would get. I don't think they bother to think about it any deeper.

Well, maybe not elsewhere in the world, but in the US, something is definitely brewing. Civil war is inevitable in this country.

And yeah, the spectrum is all 'spoken for', but in reality much of it is empty. The frequencies surrounding the CB band have been assigned to various governmental agencies for as long as I can remember and yet I have never in my life heard anything on those frequencies that remotely resembles a government agency transmission. Just outbanders.

Yeah, it does seem like that. It's like everyone is packed into these small bands with emptiness all around. They should have expanded the ham bands. I noticed a couple times that there are licensed HF broadcast stations that are actually outside the allotted bands. Maybe the govt doesn't really care so much about these frequencies cause you would never see that elsewhere. I find it strange they don't seem more interested in these frequencies considering they have good properties that no other bands have.

I guess what I get out of this is - just use whatever as long as it's empty haha.

2

General Radio Discussion / Re: Empty HF frequency band for emergency coms

« on: January 18, 2021, 1849 UTC »

Well, I think I'd manually need to trigger it anyway, so I figured that switch would be good enough for me. I won't forget it. If I used a relay, I'd need a delay circuit to another relay to PTT the transmitter and make sure the RF relay had already been opened. I guess it may work triggering at the same time, but that worries me a little. I'll look into that though.
Certainly easier to get another transceiver, but it's a shame I already have a high power transmitter that would work fine.

I checked my SDR datasheet and they say it has a max input of 10dBm, so I think it will be fine with the RF switch. I'll probably just get the switch as a backup and see what I can do with a relay.

Practically, very little activity is in the 11M International Broadcast Band, 25.670MHz - 26.100MHz. Modify a CB antenna, or just put up a dipole, as high as possible. You'll hear CB outbanders in there during "E" openings, but for the most part, it's empty space, except some broadcast NBFM Auxiliary Stations still out there, but their numbers are dwindling more each year. If you are on a hill, or can put up an 11M Vertical up as high as possible, 100 miles can be had, day, or night.

Well, I'm in the least optimal area for those higher frequency bands. I'm in a deep bowl. I figure my only way there is using the ionosphere. How reliable is skywave propagation on those bands? I've never used them. Only done VHF and lower HF and VHF is completely out of the question.

3

General Radio Discussion / Re: Empty HF frequency band for emergency coms

« on: January 18, 2021, 0736 UTC »

Making any sort of recommendation based on the current condition of frequency usage for an emergency is relatively pointless.  During such an event, band usage is going to be MUCH higher, and what is vacant today likely will be awash in various modes of data and voice.  This is also dependent on whether you are planning for near term, or in the future when propagation likely isn't known.  The best you could do is prearrange some 'calling' frequencies and times to try them, best spread over several band segments to allow for some variation in propagation, time of day, etc.  I would also include alternates located close by in case the channel you want to use is in use.

The simple solution to all these problems is ALE 

+-RH

You're probably right.
I have one more quick question. So I already have my HF broadcast transmitter and an SDR. I was wondering if I could get one of these RF switches as a quick and dirty solution so I don't need an actual transceiver on my end.
https://www.ebay.com/itm/DAIWA-CS-201A-2-Port-Coax-Switch-w-SO-239-UHF-Female-Connectors-Handles-1-5kW/111802127942

It has 60db isolation. Meaning at 1600W PEP, it will have 1.5mW going into the SDR. Is that good enough?
I know it's junky, but I'm unable to find something better. Don't want to spend a lot cause I might not use it.

Thanks.

4

General Radio Discussion / Empty HF frequency band for emergency coms

« on: January 17, 2021, 2208 UTC »

First of all, I'm not sure if I'm in the right section, so feel free to move this.

OK, so I am preparing for a societal collapse I purchased some HF ham radio transceivers. I am on my way to getting my license, however, I will need to use this as a means of communication for some people without licenses.

Assuming the system had collapsed, what HF frequency range should I plan to use that doesn't contain any military or other communications currently? Is there an empty range you could give me? A no mans land. I'm looking for something in the range 3.5 - 10 MHz cause I need to cover a 100 mile distance. My calculations show that 5 - 6 MHz would be the best choice also taking into account those people's lot size. Don't tell me just use ham anyway cause it'll be jammed.

Of course there's the pirate frequencies, but a range is something I'm looking for, not a specific frequency.

Understand that this is only to be used during emergency, so I just want to make sure I'm not interfering with anyone.

Thanks

5

Equipment / Would this dual antenna design work?

« on: August 04, 2020, 1441 UTC »

So at some point in the not too distant future, I'm going to purchase a new property with more space. I want to put up an antenna system with two antennas. One for shortwave and one for mediumwave (both for TXing and RXing). I want the minimum number of towers/supports for cost and size. The shortwave will be an inverted V and the mediumwave, inverted L. I want to insulate the base of the tower and drive it for mediumwave and for shortwave, I want to attach an inverted V to the top of the driven tower. Will this work or do I need another tower to support the V so I don't get interference or other problems? I won't TX on both at the same time if that helps.

Maybe you have a better idea?

(Note that the inverted V is not parallel with the L; it is perpendicular. It just looks like that cause I can't draw 3D.)
Here is a diagram:

6

Equipment / Re: DRM pirates

« on: August 04, 2020, 1421 UTC »

I used the DReaM software to generate DRM about 16 or 17 years ago. I had to modify my high level audio MW transmitter in some way to take the coded signal. Can't recall exactly what I had to do but there were 2 outputs from the PC. One output went into the normal audio input on the TX and the other went to a small circuit that I had to put in the output of the PLL oscillator.
I don't think the mod is needed on modern transmitters though.

It worked.............sort of.  Not having a portable DRM radio was not ideal for field tests but I was able to decode it on another PC in the house with a modified radio.

Huh, didn't realize this was that old, surprising.
I see, so it's the same way as c-quam. Maybe I'll test it someday...

7

Equipment / DRM pirates

« on: July 23, 2020, 0244 UTC »

I've been looking into DRM recently and I found these products which seem more like something a pirate might use:
http://www.nti-online.de/edrg30.htm
http://www.nti-online.de/edrg30usb.htm

I am a bit confused about the process though. It seems to me like this may actually just be an SSB transmitter cause it looks like the PC is the source of the actual DRM signal. Is that how most DRM systems work, or do the professional transmitters generate the DRM inside them?
Are most DRM signals actually an SSB signal rather than AM? Could you generate the DRM on a PC and just feed that into an old fashioned AM transmitter? Yes, it would be less efficient, but does it work?

I am trying to decide what I'm going to do with my next shortwave transmitter. Do you think a super wide 15 kHz analog SSB signal made with an SDR would be better than DRM?

8

General Radio Discussion / Re: Proposed Shortwave Station in Illinois Prompts an Objection

« on: July 14, 2020, 2133 UTC »

The whole point here is minimizing total transmission delay time. They want to be as close to the Chicago Mercantile Exchange as possible.

That's exactly it. There was a story, not sure if it was posted here or if I read it elsewhere, where some guy discovered someone that purchased an old cell tower in Chicago and attached a SW antenna to it and were using it for this purpose. They weren't a licensed SW broadcast station, but rather a ham guy or maybe even a pirate - can't remember.

In addition, I wonder how they got the approval for less than 50kW. That is the minimum power for SW broadcasting in the US. I actually looked into starting a SW station once and was turned off by the high minimum power requirement.

9

Equipment / Re: Higher highs and lower lows on MW TX antenna

« on: July 13, 2020, 2019 UTC »

Via Groundwave or Skywave? Day or night? What antenna type and dimensions?

Str.

Skywave only. Night. Antenna is 1/4 wave inverted L 60-70 ft tall, the rest horizontal.

Too little information.
Are you comparing SW with MW?

No, I'm comparing MW with MW. I wouldn't compare with SW cause that would be different.

Either way, it's not really a problem, but I find it very interesting. It's not what I would expect.

10

Equipment / Higher highs and lower lows on MW TX antenna

« on: July 13, 2020, 0817 UTC »

Compared with a MW broadcasting station, my antenna produces higher peaks and lower troughs at all times and all listening locations. Why is this? Does this have to do with angle of radiation? It is interesting that during the peaks, it's actually better than a number of MW stations at the same distance, but it dips so deep that it can't be heard sometimes. Would making the vertical section longer improve this? I always thought that angle of radiation simply has to do with the distance covered, but maybe it's more than that. If it's not angle of radiation then what is it?

11

General Radio Discussion / Why is there a gap between 7 MHz and 13 MHz?

« on: June 19, 2020, 2100 UTC »

When looking at the pirate radio logs here as well as the list... https://www.hfunderground.com/wiki/List_of_Pirate_Radio_Frequencies

You can see there is nothing noted in this range. I can understand why much higher frequencies are not used cause they are not very reliable. But in this range, I would expect easier antenna installation with a higher efficiency at lower heights. Also much shorter for smaller lots and increased daytime range. Maybe the doughnut is too big (bad local)? By doughnut, I mean the empty area between the groundwave and the skip zone. Is there just no space for it? I don't know this band too well.

12

Bacon, BBQ, Beef, And More / Frankie's Free Range Meat

« on: June 19, 2020, 1923 UTC »

I am not affiliated with them, but I know the guy cause he has a youtube channel about nutrition and about some conspiracies I don't necessarily agree with, but a good guy. Hopefully, you don't mind this advertisement Chris
With the current beef supply limits in the US, I figured it would be good to let people know about this source. They sell in bulk at some of the cheapest prices online. All grass fed mostly from NY farms or Australia. He complains about not making much money from his low costs (and it's not just a marketing ploy). In addition, most everything is sourced directly, so there should be no supply chain issues unless too many people purchase.

https://frankiesfreerangemeat.com/

13

Bacon, BBQ, Beef, And More / Re: Why is the World Health Organisation Anti-Meat?

« on: June 19, 2020, 1913 UTC »

Because the world health organization is funded by eugenicists. It has nothing to do with health and all to do with money and power. I know this forum is not for debates, so I'll just leave it here and not follow up.

14

General Radio Discussion / Re: Pirate radio laws outside the US

« on: June 10, 2020, 1036 UTC »

I wonder, are there any countries that have no regulations - like no FCC at all? It would be so fun to be able to pirate 24/7 and maybe even have commercials to make money.

15

Equipment / Re: What are you using for SWLing?

« on: June 10, 2020, 0432 UTC »

I just use an AirSpy HF+ and a mediumwave inverted L. I generally DX mediumwave or low shortwave signals. In this day and age, I don't see an advantage of a "real" receiver. SDRs have surpassed traditional receivers in both cost and performance. The AirSpy is probably not the best thing out there, but for the pricepoint, it's very good. Better and less complicated than an RTLSDR with downconverter.